1. Field
The present disclosure relates to a driving force transmitting apparatus.
2. Description of the Related Art
An example of a driving force transmitting apparatus for an automobile includes a frictional engagement device, such as a clutch or a brake, provided around a rotating shaft (see, for example, Japanese Unexamined Patent Application Publication No. 2012-218669 (hereinafter referred to as Patent Document 1)). The driving force transmitting apparatus described in Patent Document 1 includes a clutch capable of switching between a state in which rotation is transmitted between two coaxially arranged rotating shafts and a state in which no rotation is transmitted between the two rotating shafts. The clutch includes a clutch housing fixed to one of the rotating shafts, a clutch hub fixed to the other rotating shaft in a region inside the clutch housing, and a frictional engagement unit. The frictional engagement unit includes a plurality of friction members fixed to the clutch housing and a plurality of friction members fixed to the clutch hub. The friction members fixed to the clutch housing and the friction members fixed to the clutch hub are alternately stacked in an axial direction in the clutch housing.
The clutch includes a piston member for pressing the frictional engagement unit in the direction in which the friction members are stacked, a piston housing that contains the piston member, and a piston chamber that is defined between the piston housing and the piston member and in which an oil pressure for moving the piston member toward the frictional engagement unit is generated. The clutch is engaged when the piston member is moved by the oil pressure generated in the piston chamber and the frictional engagement unit is pressed by the piston member.
The driving force transmitting apparatus including the above-described clutch includes an oil pressure sensor for detecting a clutch pressure (oil pressure in the piston chamber). The torque transmitted by the clutch is controlled in accordance with a clutch pressure detected by the oil pressure sensor.